SAES-422 Multistate Research Activity Accomplishments Report

Sections

Basic Information
Additional Info

Status: Approved

Basic Information

Project No. and Title: NC_old1186 : Water Management and Quality for Ornamental Crop Production and Health
Period Covered: 10/01/2015 to 09/30/2016
Date of Report: 09/26/2016
Annual Meeting Dates: 06/22/2016 to 06/24/2016

Participants

A full list of participants is attached.

Attached file:

2016-NC-1186-attendee-list.docx

Brief Summary of Minutes of Annual Meeting

The 2016 annual meeting for NC−1186 multistate research project was held in conjunction with the NE- 1335 Controlled environments group on Long Island, NY June 22- 24 2016. The meeting started with a tour of the Long Island Horticultural Research and Extension Center, followed by a graduate student poster session. Afterwards, we conducted a dinner/social to facilitate interactions between the two groups.

The business meeting began Thursday morning, with a welcome by Mark Bridgen, our host from Cornell University. After that, we had brief introductions of all of the participants, followed by station reports from the group, which was facilitated by Stephanie Burnett (Chair of NE 1335) and Rosa Rodales. There were 25 attendees from 15 institutions comprised of USDA ARS scientists, university faculty, students, and staff.

In the afternoon, we had a group discussion regarding areas of interest and overlap between the groups led by John Majsztrik. The discussion centered around areas of potential collaboration of the group. After this discussion, we broke up into 3 groups to further discuss collaboration efforts in areas of overlap for both NE 1335 and NC 1186.

After the breakout sessions, the NE 1335 and NC 1186 groups held their individual business meetings. Amanda Bayer (University of Massachusetts) was elected secretary by unanimous vote. The following meeting dates and locations were agreed upon by the group, with exact dates and details to be worked out by the executive committee and hosting institution. June 2017 in Asheville, NC (host Anthony LeBude) (potential dates June 12-14 or 14-16); March 2018 in Gainesville, FL (host Paul Fisher); and June 2019 Monterey CA (host Lorence Oki). The suggestion was made to include a grower workshop with all NC1186 meetings, since they would benefit the local growers, and travel costs would be minimal since speakers would already be attending the NC 1186 meeting.

On June 24 there was a tour of 4 local nurseries.

Attached file:

Joint-NE-1335-and-NC-1186-meeting-minutes.docx

Accomplishments

California

The PIs’ research groups continue to work on the California portion of the Clean WateR3 project characterizing nursery runoff, and have installed instruments and dataloggers at two cooperating nurseries to measure the volumes of water obtained from water sources (including captured runoff) and applied in irrigation. Water samples have been collected and are being analyzed for nutrients and water-borne plant diseases. This information will be used to determine methods to improve irrigation efficiency to reduce water use, examine challenges and develop solutions for recycling, and study remediation methods to remove pathogens and other pollutants prior to reuse.

We have submitted a manuscript for publication describing the removal of Tobacco mosaic virus (TMV) using slow sand filters. We found that slow sand filters are capable of removing TMV from captured irrigation runoff so that the water can be reused for irrigation. This will be the first report of the removal of a plant pathogenic virus from runoff water in a replicated study using this method. Slow sand filters are a biological water treatment method that have been shown to successfully remove water molds from runoff water.

Connecticut

The University of Connecticut observed that when biofilm was present on the irrigation pipes Pythium root-rot in poinsettias was lower compared with plants irrigated with new pipes. This is the first study to evaluate the interaction of biofilm with plant pathogens in irrigation. In a separate study, we observed that biofilm accumulated faster and more abundant in PVC pipes compared with polyethylene pipes.

Florida

University of Florida constructed a small-scale granular activated carbon system to test the removal capability of paclobutrazol. Paclobutrazol is an active ingredient used in plant growth regulators to control plant height. A 0.05 mg·L^-1 paclobutrazol solution was passed through this small-scale, 0.50 to 4.75 mm particle size (8x30 mesh) coconut coir GAC system at 6L·minute^-1. A randomized complete block design was used with six contact times (0, 12, 24, 36, 47, or 59 seconds), which corresponded to 0, 1.9, 3.7, 5.6, 7.5, or 9.4L of empty filter housing volume (excluding the carbon). 15mL of each GAC-treated solution were then applied to broccoli [Brassica oleracea ‘Waltham 29’] seed and begonia [Begonia x semperflorens-cultorum ‘Super Olympia White’] seedlings. Broccoli hypocotyls at 14 days were 103% longer and begonia dry mass was 36% greater when treated with solutions that had a contact time of 59 seconds GAC compared with the 0seconds GAC treatment. With the highest GAC level, begonia dry mass was the same as for plants treated with a zero paclobutrazol solution. However, the broccoli hypocotyl length was 10% shorter for plants treated with 59 seconds GAC compared with a zero paclobutrazol solution. Analysis of paclobutrazol concentration using liquid chromatography-mass spectrometry (LC-MS/MS) found that paclobutrazol concentration decreased by 90% or 99% with a contact time of 12 seconds or 59 seconds GAC, respectively. Overall, this experiment showed that granular activated carbon has the potential to remediate paclobutrazol from irrigation water to below biologically-active concentration.

Indiana

Little is known about the P accumulation patterns and P utilization efficiency in container crops and there are only a few reports on the effects of P fertilization on partitioning in relation to their productivity. Such information is critical as it will help design more efficient management strategies for P fertilizer by better aligning the P requirements of crops and the application amount and timing of the nutrient. The objective of our study was to critically analyze the effects of P on shoot and root growth, phosphorus (P) partitioning and P utilization efficiency in lantana. Our study refines the effects of P fertilization on plant growth, and provides critical information on the biomass accumulation during vegetative and reproductive growths, in relation to P accumulation and partitioning in lantana. Improved cultural practices will help growers to stay in business while complying with federal and state regulations, which are likely to become more stringent with time.

Massachusetts

UMass is continuing to establish a research program to further examine how plant growth is effected by irrigation practices, how irrigation can be manipulated to control plant growth, and to look at how Massachusetts nurseries can improve irrigation efficiency.

Mississippi

New cut flower crops, such as tall bearded iris, are of value to the floral industry, but little may be known about the nutrient requirements for the commercial productions of such crops. A study at Mississippi State University evaluated growth, flowering, and nutrient use efficiency of reblooming Iris ‘Immortality’ using nitrogen supplied via irrigation. This study determined that relatively higher rates of nitrogen encouraged a second blooming of Iris ‘Immortality’ and indicated that a N rate of 10 mM was optimal for nitrogen uptake efficiency. Also, higher N rates supplied the prior year are recommended to improve production of inflorescence stems in the spring.

New Jersey

Rutgers University has found that container-grown ornamental plants irrigated (short-term) with laundry graywater irrigation are similar in growth and quality to those irrigated with good quality water sources (municipal tap and well-water). Addition of bleaching agents (i.e. Clorox) to graywater, however, have been found to produce toxic effects on several plant species, attributed to the presence of high total and free chlorine concentrations (45 to 60 ppm). A preliminary landscape irrigation study with graywater has also shown that the presence of bleach in this water source leads to reduced soil biological biomass and diversity compared to control plants irrigated with well water. Studies are underway to experimentally validate integrated nutrient diagnosis norms (DRIS= Diagnosis and Recommendation Integrated System, and CND= Compositional Nutrient Diagnosis) we have generated for greenhouse-grown cut roses. To date, theoretical validation of these norms has found that they are suitable for rose crop nutrient status diagnosis, allowing for the correlation of nutrient balance indexes with crop flower productivities across a range of cultivars, plant ages, rootstocks and production systems (i.e. soils, soilless substrates, hydroponics).

North Carolina

NC State sampled source water quality growers use for irrigation in over 60 nurseries in 18 counties in eastern North Carolina during late summer 2015 ( See full station report for Table 1). They determined that more than 66% of nurseries are irrigating with high pH water (>7.0) in summer caused by algae production in surface waters. The effect of high pH irrigation water on plant growth and quality is under investigation while NC Cooperative Extension agents are working with local growers to decrease algae production in surface waters.

Ohio

USDA-ARS in Wooster, OH, determined the mechanism by which parboiled rice hulls provide weed control in container crops. Parboiled rice hulls are a clean, light-weight, OMRI-approved organic mulch product that can be used for controlling weeds in nursery containers. Weed seed and spores (from liverworts and mosses) that land on top of the mulch surface fail to establish due to volumetric water content of the mulch layer. Compared to pine bark and sphagnum peatmoss, rice hulls retain very little water from an irrigation event, and they dry quickly from what little water they do retain. For weed seeds present on the surface of the container at the time of mulch application, rice hulls must form a physical barrier to prevent weed establishment. A mulch layer at least 1.25 cm thick is needed to physically impede weed establishment from beneath the rice hull mulch layer. Steam or how-water can be used to sterilize reused plastic propagation pots and trays and effectively kill weed seed attached to the plastic. Seeds of many weeds, most notably bittercress (Cardamine flexuosa) and creeping woodsorrel (Oxalis corniculata), stick to plastic containers and trays and are reintroduced into the production system when these containers and trays are reused. Bittercress seed exposed to 70 °C hot-water for 30 minutes were killed 100%, while seed exposed to 90 °C hot-water for just 10 minutes were killed 100%.

South Carolina

Researchers at Clemson University evaluated aquatic plants species for their susceptibility to plant pathogens by screening eleven aquatic plant species in repeated laboratory trials to evaluate susceptibility to plant pathogens. Plant species screened include: Agrostis alba, Andropogon glomeratus, Carex stricta, Canna flaccida, Canna ×generalis ‘Bird of Paradise,’ Iris ensata ‘Rising Sun’, Pontederia cordata, Sagittaria latifolia, and Typha latifolia. Iris and canna species supported limited or no growth and reproduction of examined Phytophthora spp., indicating they are not susceptible to infection by Phytophthora and can be used in future studies of “designer” vegetative channels. Additional screening of plant species is planned to verify alternate susceptibility. Researchers at Clemson University and Virginia Tech worked together to develop multiple “tools” grower can use to make decisions. The first developed model is related to water treatment – disinfection via various chemicals. The water treatment model will be tested and validated this year. Researchers at Virginia Tech, Clemson University, North Carolina State University, and University of New Hampshire collaborated to develop and beta test a comprehensive crop production tool to help the technology-savvy grower manage water and fertilizer. This research funded by the Horticulture Research Institute and the American Floral Endowment will assist nursery and floriculture producers The “app” will assist growers in making on-the-go decisions, providing them with historical records, saving time and money.

Tennessee

The University of Tennessee established 3 independently controlled irrigation plots at three commercial nurseries to examine water use, container drainage (leachate) volume, and plant growth. Plants include ornamental cherries, hydrangeas, junipers, and dogwoods. Plants were automatically irrigated by one of three sensor-based regimes: 1) an on-demand (OD) irrigation system based on a specific container substrate moisture content, 2) a leachate-based system, or 3) a daily water use system. In each case the system was compared with the nursery’s standard daily timer-based irrigation. In general, plants irrigated by the sensor-based systems stayed more moist, experienced fewer moisture level extremes, and use less water. All three treatments used significantly less water than the common industry practice of applying 0.7-1.0 inch per day. This research is on-going and will be continued over several seasons to determine if conservative, technology driven irrigation scheduling can reduce water consumption without reducing growth or slowing production time and determine, which, if any, of the sensor-based systems is best.

Texas (truncated)

We continue to study on the salt tolerance of important ornamental species and drought tolerance and irrigation management of ornamental plants. In the past 12 months, the following were studies.

Study 1: Salt tolerance of ten aster perennials was evaluated in a greenhouse experiment. Plants were irrigated with nutrient solution at electrical conductivity (EC) of 1.2 dS∙m^-1 (control) or saline solutions at EC of 5.0 or 10.0 dS∙m^-1(EC 5 or EC 10) for five weeks. Results indicated that gregg’s mistflower, skeleton-leaf goldeneye, and lavender cotton were the most salt tolerant species with less reductions in shoot DW at elevated salinity. Damianita and the four daisies, i.e., blackfoot daisy, copper canyon daisy, four-nerve daisy, and shasta daisy, and aromatic aster and zexmenia were salt sensitive.

Study 2: Nine ornamental species were irrigated with a nutrient solution and saline solution at three different electrical conductivity rates and were assessed for growth and physiological responses. Results indicated that orange peel jessamine and mexican hummingbird bush were the most salt tolerant in the trials, while flame acanthus, rock rose, and ‘Dark knight’ bluebeard were moderately salt-tolerant. Cardinal flower, mexican false heather, and butterfly blue plants were moderately salt sensitive, while Eastern red columbine was the most salt sensitive among the species.

Study 3: the salt tolerance of six Lamiaceae species was determined by quantifying their growth and physiological responses. Our results indicated that Texas betony was the most salt tolerant, Russian sage and spotted dead nettle were moderately tolerant, while bugleweed, Mexican oregano, and cherry skullcap were the least salt tolerant.

Angelonia angustifolia ‘Angelface Blue’ liners were grown until the marketable stage with irrigation at soil moisture content (SMC) of 20 or 40% using Watchdog 1000 series SMC monitors. At the end of production, 40% SMC plants had significantly larger growth index (GI=(width 1+width 2)/4 + height/2) and dry biomass than 20% SMC plants and 20% SMC plants had shorter internodes. This is physiological evidence suggesting plants that were water stressed during production were more acclimated to the retail environment. Our results demonstrate that while conserving water, controlled irrigation at a lower SMC can produce high quality plants that have equal or superior shelf life to those that are irrigated at high levels.

Virginia

Surveyed nursery and greenhouse growers in Virginia regarding best management practices (BMPs). 60 respondents reported BMP use, which included buffer strips, irrigation scheduling and optimized irrigation efficiency, water capture and collection, plant need based water application, grouping plants by water needs, integrated pest management, and controlled-release fertilizers. Growers reported that their sources of information about BMP use included learning on their own (81%), observing what others in the industry did (62%), extension publications (60%), vendors (21%), and the BMP manual (13%).

Filter socks were successful at removing sediment and bound agrichemicals at grower collaborator sites; however, filter socks did result in undesirable water retention / damming in a few locations that resulted in a perceived increase in disease potential and wet roadways.

Owen and Altland investigated organic acids and solids leached from soilless substrates to better understand their interaction with soilless substrates chemical amendments, namely phosphorus, and subsequent water quality. A study was conducted utilizing three pine bark sources commonly used for containerized crop production in the southeastern, Midwest and mid-Atlantic US. Replicates of each bark from three source was packed 6” PVC columns and leached over a 12-day period. Effluent samples were collected every two days and analyzed for total suspended solids, organic constituents, and elemental concentration and content. Preliminary results indicate leaching of total suspended solids vary widely from each source, contributing 250 to 1000 mg of solids from a #1fallow container.

Impacts

California: From a new member of the group, my research projects include: the development of a method to assess plant salinity tolerance using microcalorimetry, measurement of landscape plant water use, treatment of irrigation runoff using slow sand filters, characterization of nursery water movement (hydrology), and the evaluation of a new soil moisture sensor technology. I am Co-Director of the UC Nursery and Floriculture Alliance, an extension and outreach program that provides education and technical training to growers. The California project PI is a Co Director of the University of California Nursery and Floriculture Alliance (UCNFA) that provides education and technical training to California greenhouse and nursery growers (ucnfa.ucanr.edu). In 2015, we provided the ABCs of Plant Pathology to 47 attendees in English and 42 in Spanish. The California Nursery Conference was held in October 2015 and presented topics on disease and pest management to 93 attendees. In 2014, 327 attendees were present at 8 workshops and a conference that covered topics on basic horticulture (in English and Spanish), biological control of pests, nursery and greenhouse pest control (in English and Spanish), and water conservation and irrigation efficiency.
Connecticut: Biofilm is a widespread problem in irrigation pipes. Current practices to control biofilm are reactive (aim to eliminate established biofilms) and not effective. Our program aims to understand how biofilm establishes and accumulates in pipes and aim to identify critical thresholds for treatment.
Florida: Recapturing and recirculating irrigation water increases water use efficiency and availability for ornamental crop production. However, recirculated irrigation water can contain plant growth regulators, pesticides, herbicides, and other agrichemicals that can affect overall crop quality. Initial research at the University of Florida has shown that granular activated carbon may be a technically and financially feasible technology to remove the plant growth regulator paclobutrazol from irrigation water. The University of Florida is currently working with ornamental nursery operations that are interested in adopting this technology. With this collaboration, the ornamental industry can be directly shown the benefits of activated carbon technology. Activated carbon may also be effective in removing various other agrichemicals from water. Further studies will take place to test the removal capability of acephate, bifenthrin, chlorpyrifos, and imidacloprid using granular activated carbon. The standard concentrations of these chemicals will be based off effluent concentrations measured from a controlled run-off experiment. Management strategies to monitor the effectiveness of granular activated carbon over time are also being developed, along with analysis of installation and operating cost. This can allow nurseries using this technology to determine the shelf-life of their carbon with minimal cost and labor. Overall, this water treatment technology can benefit the nursery industry by improving recirculated irrigation water quality and reducing the environmental impacts from crop production.
Indiana: In order to determine P requirements of ornamental plants, research was conducted at Purdue University using lantana which were grown at different P levels. Results indicate that plants require a relatively high P during the early stages of growth to promote vegetative growth, and sufficient P supply during reproductive growth to optimize plant productivity. This information is critical to better manage production systems and to mitigate the environmental concerns.
Mississippi: Because of their showy, colorful flowers and sword-shaped leaves, tall bearded iris (Iris germanica) has potential as a specialty cut flower. A better understanding of how reblooming, tall bearded iris responds to fertilizer N rates and how plants use stored N in relation to spring-applied N would help to optimize growth and flowering and improve N fertilizer management. Former graduate student Xiaojie Zhao determined that Iris ‘Immortality’ is capable of a second blooming in a growing season, with this second blooming dependent on N fertilization rate during the same year. A relatively high N rate is recommended to produce a second blooming. Nitrogen uptake efficiency was greatest using a 10 mM N rate of nitrogen via fertigation.
New Jersey: The use of alternative irrigation water sources is imperative to the green industries (nursery, greenhouse landscape), as their dependence on high quality water sources is jeopardized by climate change, competition and allocation to other priority uses. Studies on alternative irrigation water sources at Rutgers University are evaluating the short- and long-term effects of sources like reclaimed water and graywater on nursery, greenhouse and landscape plants in comparison to traditional, high-quality, water sources. Results to date suggest that systematic tracking of water quality parameters, and adjustments to irrigation management practices could allow for satisfactory use of these alternative water sources. The long-term effects of these water sources on the chemical, physical and biological properties of soils are currently being assessed.
North Carolina: NC State has determined that more than 50% of growers in eastern North Carolina have poor quality source water that is used for irrigation as recommended by best management practices guide for producing container plants. An integrated approach to reduce algae growth in surface waters as well as reduce irrigation water pH has the potential to increase plant growth by 10%.
Ohio: USDA-ARS in Wooster, OH determined the mechanism of action by which rice hulls provide weed control in nursery containers. Based on these results, more clear guidelines can be provided for nursery producers using rice hulls for weed control in newly potted containers or older and more established containers. USDA-ARS in Wooster, OH has documented the temperature and exposure time needed for killing bittercress seeds attached to reused plastic propagation trays and containers. Refined temperature and exposure times will allow more precise management and energy conservation when using this technology for weed management.
South Carolina: Use of alternative water resources (e.g., recycled, municipal reclaimed water, etc.) by greenhouse and nursery growers is critical for their continued economic sustainability. Water quality in alternative sources may be poor, reducing crop growth. We are quantifying the quality of alternative water sources (in various regions within the US) and developing decision support tools to help growers make informed decisions about how to clean their water. Use of alternative water source will decrease grower demand for potable water sources, while maintaining access to viable water sources for crop production. Reducing nitrogen and phosphorus levels in surface waters help to limit algal blooms. For most growers, water treatment options are limited by economic and site-specific constraints. We used floating treatment wetlands to reduce nutrient levels in ponds to control algae. Plants in the floating wetlands absorbed 17-290.6 g of N per m2 and 1.1 to 48.4 g of P per m2. Floating wetlands absorbed nutrients, limiting nutrients available to algae and improving water quality.
Tennessee: Increasing regulation, public interest in sustainable practices, and droughts have increased nursery producer awareness of the need to more conservatively use natural resources such as water during agricultural production. The University of Tennessee has shown that sensor-based irrigation scheduling reduces water by 50% for cherries, 63% for junipers and hydrangeas, and between 44 and 70% for dogwoods, depending on species.
Texas: By using non-potable water sources such as reclaimed and brackish water to irrigate landscapes and nursery crops, the supply of freshwater can be extended and saved for other beneficial purposes.
Virginia: Substrates were engineered using conventional components (i.e. bark, peat, coir) to reduce applied water while maintaining or increasing crop growth. Soilless substrate amendments such as lime and micronutrients reduced effluent phosphorus and could potentially be a phosphorus best management practice. Reduced phosphorus controlled release fertilizers were successful at producing Ilex crenata Thunb. ‘Helleri’ (holly) and Hydrangea macrophylla ‘P11HM-11’ Bloomstruck™; however, each required varying amount of P to maximize growth demonstrating intra-taxa variability in P requirements.

Publications

Published written works - Refereed Journal Articles and Book Chapters

California

Newman, J.P., J.N. Kabashima, D. Merhaut, D.L. Haver, J. Gan, and L.R. Oki. 2014. Controlling runoff and recycling water, nutrients, and waste. In: Container Nursery Production and Business Manual. J.P. Newman (ed.) University of California Division of Agriculture and Natural Resources, Richmond, CA. pp.95-118.

Oki, L.R. and J.H. Lieth. 2014. Mechanization and automation. In: Container Nursery Production and Business Manual. J.P. Newman (ed.) University of California Division of Agriculture and Natural Resources, Richmond, CA. pp.45-58.

Nackley, L.L., C. Barnes, and L.R.Oki. 2015. Investigating the impacts of recycled water on long-lived conifers. AoB Plants. 7: plv035. doi: 10.1093/aobpla/plv035.

Connecticut

Altland, J.E., L. Morris, J. Boldt, P. Fisher, and R. Raudales. 2015. Sample container and storage for paclobutrazol monitoring in irrigation water. HortTechnology 25:769-773.

Raudales, R.E., P. Fisher, C. Hall. Submitted. Cost Analysis of Water Treatments in Irrigation. Irrigation Science

Florida

Oliveira, S.F., P.R. Fisher, J. Huang, and S.C. Mello. 2016. Strategies to provide fertilizer for both production and consumer phases of petunia. HortTechnology 26:164-175.

Meador, D.P., P.R. Fisher, C.L. Guy, P.F. Harmon, N.A. Peres, Max Teplitski. 2016. Using a dehydrated agar to estimate microbial water quality for horticulture irrigation. Journal of Environmental Quality Mar-Apr 2016. 0. doi:10.2134/jeq2015.03.0130.

Dickson, R.W., P.R. Fisher, W.R. Argo, D.J. Jacques, J.B. Sartain, L.E. Trenholm, T.H. Yeager. 2016. Solution ammonium:nitrate ratio and cation/anion uptake affect the acidity or basicity produced by three floriculture species in hydroponic nutrient solutions. Scientia Horticulturae 200:36–44.

Altland , J.E., L. Morris, J. Boldt, P.R. Fisher, and R.E. Raudales. 2015. Sample container and storage for paclobutrazol monitoring in irrigation water. HortTechnology 25:769-773.

Fisher, P., and R. Raudales. 2016. Minimize build up in your water pipes. Greenhouse Grower. June 2016:65, 66, 68.

Fisher, P. 2016. Pinpoint toxicity in your pond water. Greenhouse Grower. May 2016:46, 48, 50.

Fisher, P., G. Grant, V. Zayas, R. Raudales, J. Altland, and J. Boldt. 2016. New technology development in water treatment. Greenhouse Grower Technology. May/June 2016:20, 22.

Fisher, P.R. 2016. Unclog drip emitters in your greenhouse. Greenhouse Grower. April 2016:42-44.

Fisher, P.R., J. Huang, M. Paz, and R. Dickson. 2016. Having success with organic growing mixes. GrowerTalks Jan 2016:68-72.

Indiana

Kim, H.J. and X.X. Li. 2016. Effects of phosphorus on shoot and root growth, partitioning and phosphorus utilization efficiency in lantana. HortScience. (Accepted)

Massachusetts

Bayer, A., J. Ruter, and M.W. van Iersel. 2015. Optimizing Irrigation and Fertilization of Gardenia jasminoides for Good Growth and Minimal Leaching. HortScience. 50:994-1001.

Mississippi

Zhao, X., G. Bi, R.L. Harkess, J.J. Varco, and E.K. Blythe. 2016. Spring nitrogen uptake, use efficiency, and partitioning for growth in Iris germanica 'Immortality'. HortScience 51:563-566.

Zhao, X., G. Bi, R.L. Harkess, J.J. Varco, T. Li, and E.K. Blythe. 2016. Nitrogen fertigation rates affect stored nitrogen, growth and blooming in Iris germanica 'Immortality'. HortScience 51:186-191.

New Jersey

Wu, S., Y. Sun, G. Niu, J. Altland, and R.I. Cabrera. 2016. Response of 10 aster species to saline water irrigation. HortScience 51(2): 197-201.

North Carolina

Fulcher, A., A.V. LeBude, J.S. Owen, Jr., S.A. White, and R.C. Beeson. 2016. The next ten years: Strategic vision of water resources for nursery producers. HortTech. 2:121-131.

Ohio

Altland, J.E., Zellner, W., Locke, J.C., and Krause, C.R. 2015. Micronutrient availability from steel slag amendment in peatmoss substrates. HortScience. 50:1715-1720.

Zellner, W.L., Friedrich, R.L., Kim, S., Sturtz, D.S., Frantz, J., Altland, J.E., Krause, C.R. 2015. Continuing assessment of the 5 day sodium carbonate ammonium nitrate extraction assay as an indicator test for silicon fertilizers. Journal of AOAC International. 98(4):890-895.

Altland, J.E., L. Morris, J. Boldt, P. Fisher, and R. Raudales. 2015. Sample container and storage for paclobutrazol monitoring in irrigation water. HortTechnology 25:769-773.

Altland, J.E. and J.C. Locke. 2015. High rates of gasified rice hull biochar affect geranium and tomato growth in a soilless substrate. J. Plant Nutr. (Accepted, In Press).

Altland, J.E., Locke, J.C., and Zellner, W. 2016. Micronutrient availability from steel slag amendment in pine bark substrates. J. Environ. Hort. (Accepted, In Press).

Altland, J.E. and K.Y. Jeong. 2016. Dolomitic lime amendment affects pine bark substrate pH, nutrient availability, and plant growth: A review. HortTechnology (Submitted, In Review).

South Carolina

Fulcher, A., A.V. LeBude, J. S. Owen, Jr., S. A. White and R. C. Beeson. 2016. The next ten years: Strategic vision of water resources for nursery producers. HortTechnology 26:133-140.

Tennessee

Yeary^M, A. Fulcher, and B. Leib. Nursery irrigation: A guide for reducing risk and improving production. UT Extension Publication PB 1836. https://extension.tennessee.edu/publications/Documents/PB1836.pdf

Fulcher, A., A.V. LeBude, J.S. Owen, S.A. White and R.C. Beeson. 2016. The next ten years: Strategic vision of water resources for nursery producers. HortTechnology 26(2):121.

Texas

Jacobson, A.B., T.W. Starman, and L. Lombardini. 2015. Substrate moisture content effects on growth and shelf life of Angelonia angustifolia. HortScience 50(2):272-278.

Wu, S., Y. Sun, G. Niu, G.L. Grimaldo and A. Castro. 2016. Responses of six Lamiaceae landscape species to saline water irrigation. Journal of Environmental Horticulture 34(1): 30-35.

Wu, S., Y. Sun, and G. Niu. 2016. Morphological and physiological responses of nine ornamental species to saline water irrigation. HortScience 51(3): 285-290.

Wu, S., Y. Sun, G. Niu, J. Altland, and R. Cabrera. 2016. Response of 10 aster species to saline water irrigation. HortScience 51(2): 197-201.

Wang, X., M. Gu, G. Niu, P.A. Baumann. 2015. Herbicidal activity of mustard seed meal (Sinapis alba ‘IdaGold’ and Brassica juncea ‘Pacific Gold’) on weed emergence. Industrial Crops and Products 77: 1004-1013.

Sun, Y., G. Niu, R. Wallace, J. Masabni, and M. Gu. 2015. Relative salt tolerance of seven strawberry cultivars. Horticulturae 1:27-43; doi:10.3390/horticulturae1010027.

Sun, Y., G. Niu, and C. Perez. 2015. Relative salt tolerance of seven Texas Superstar® perennials. HortScience 50:1562-1566.

Sun, Y., J. Masabni, and G. Niu. 2015. Simulated seawater flooding reduces the growth of ten vegetables. HortScience 50(5):694-698.

Sun, Y., G. Bi, and G. Niu. 2015. Foliar application of dikegulac sodium increases branching of Hydrangea macrophylla ‘Merritt’s Supreme’. HortTechnology 25(3):306-312.

Virginia

Fulcher, A., A.V. LeBude, J. S. Owen, Jr., S. A. White and R. C. Beeson. 2016. The next ten years: Strategic vision of water resources for nursery producers. HortTechnology 26:133-140.

Fields, J.S. and J.S. Owen, Jr. 2015. Utilizing the HYDRUS model as a tool for understanding soilless substrate water dynamics. Acta Hort. (in press, presented at ISHS Intl. Substrate and Compost Symposium)